Evaluation of phytoextraction and biochar as a remedial approach for treating agricultural soils impacted with metals

农业土壤的金属污染是一个世界性的问题。由于工业过程和/或金属污染废物的不当处置做法，加拿大和海外的许多耕地基本上已变得无法使用。处理金属污染的传统修复方法包括挖掘和填埋、焚烧、土壤清洗、固化/稳定和玻璃化。这些方法虽然有效，但成本高昂，可能会对土壤质量产生负面影响，或导致土壤完全破坏。这项研究项目评估了在中国和加拿大应用两种互补的植物方法(即植物技术)修复大片农田的可行性。在这两种情况下，土壤覆盖面积很大，主要受到镉的污染，但也有其他 金属包括镍、铜、锌和铅。植物提取是指利用维管植物将土壤污染物提取到植物根中，并将其转移到地上部分，然后再进行收获、堆肥和处理。这项技术将与使用生物炭固定土壤基质中的金属形成对比，生物炭是一种非常稳定的有机物，它也改善了土壤质量。通过同时探索使用这两种植物技术修复来自加拿大安大略省中国和博隆附近河池附近农业区金属污染土壤的有效性，马洛兹工程公司希望识别出最重要的现场特定变量，并能够将发现应用于 其他商业网站。这种替代的“绿色技术”将是一种方便且经济高效的工具，可以添加到马洛兹的补救技术“工具箱”中。

Contamination of agricultural soils with metals is a word wide problem. As a result of industrial processes and/or inappropriate disposal practices of metal-contaminated wastes, much of the arable land both in Canada and overseas has become essentially unusable. Traditional remediation methods to deal with metal contamination include excavation and landfilling, incineration, soil washing, solidification/stabilization, and vitrification. Although effective, these methods are costly and can negatively affect soil quality or result in its complete destruction. This research project assesses the feasibility of applying two complementary plant-based approaches (i.e. phytotechnologies) to remediate large tracts of agricultural land in China and Canada. In both cases, the soils cover a large area and are contaminated predominantly with cadmium, but also with other metals including nickel, copper, zinc, and lead. Phytoextraction refers to the use of vascular plants to extract soil contaminants into plant roots and translocate them to the shoots, which are then harvested, composted, and disposed of. This technology will be contrasted with the immobilization of metals in the soil matrix using biochar, a very stable form of organic matter, which also improves the soil quality. By simultaneously exploring the efficacy of using these two phytotechnologies to remediate metal-contaminated soils from agricultural areas near Hechi, Guanxi Province, China and Bolon, Ontario, Canada, Malroz Engineering Incorporated hope to discern the most important site-specific variables, and be able to apply the findings to other commercial sites. This alternative 'green technology' will be a convenient and cost-effective tool to add to Malroz's 'toolbox' of remediation technologies.